What do you wear when the season is changing? HELP

When can you start full out wearing your fall and/or summer wardrobe? I'm terrible at season transitions and thesefall-summer hybrid outfits are making me feel schizophrenic.

Like, what are the rules to incorporating warmer clothing/less clothing, do you slowly introduce a scarf here or daisy dukes there OR do you have to fullout switch? Like one day you just walk outside and proclaim "FROM THIS DAY FORTH IT IS SUMMER MOTHERFUCKERS"(while quietly shivering in your flip flops as the person passing you in a puffer jacket stares skeptically).